The present invention relates to a device and a method of metering and displaying immediate and/or accumulated energy consumption at a place of consumption, such as electricity, water or heating consumption in a household. The invention moreover relates to a method of calibrating the device.
DE-A1-25 53 237 and DE-A1-33 20 253 disclose devices of the above-mentioned type in which values of consumption are displayed in a plurality of display units, in which each row corresponds to one type of consumption, and each column displays various data for the consumption. It is thus known to display the energy consumption on a display in which the figures displayed indicate the consumption of kilowatt hours (kWh), calories amount (m3) of water or gas, depending on the consumption being metered. In addition to the instantaneous consumption, the figures in the other columns indicate the price per unit of consumption, a previous consumption as well as comparisons of the measurements. It is moreover known from DE-A1-25 53 237 to calculate monthly or annual consumption.
The drawback of these devices is that they are complicated to install, service and read. Installation requires that the device is prepared with average values of the consumption, prices of consumption units, etc. Also, corrections must currently be made for price increases in the consumption units. All this requires a good deal of knowledge about how the device works, just as it is necessary to possess some technical insight in order to operate the device, both at start and at the current data inputs. Moreover, it is a prerequisite that the user, in order to understand the various display units, has a certain knowledge of the various types of consumption. Finally, these devices are extremely exacting in terms of operation and are therefore relatively large. They are therefore difficult to mount, since, owing to other considerations, they will frequently be mounted partly concealed in the rooms in which they are installed.
The closest it is possible to get to such devices is energy meters, e.g. as shown in U.S. Pat. No. 4,686,460, in which a given consumption is displayed by a visual indication and is read by the energy supplier at regular intervals e.g. annually in connection with the billing.
Here, however, there is no form of current display of the energy consumption, so that the consumer can get an overview of his energy consumption and his expenses incurred thereby. This is possible with the initially mentioned devices for the display of the energy consumption.
With these devices, however, it is difficult to get such an overview of the energy consumption, and the invention is therefore intended to provide a device for metering and displaying energy consumption which is simple to read and has a discrete size and design, and which does not require much technical knowledge on the part of the user.
The invention comprises a device and a method of the type mentioned in the opening paragraph, said device comprising a recording unit which, on the basis of regular measurements, records and sums up an intermediate energy consumption and stores these measurements for the calculation of an average consumption, a display comprising at least one display unit capable of displaying, on a percentage scale, the relationship between an accumulated energy consumption and the calculated average consumption for a selected period of time.
This provides a simple device which is self-calibrating through accumulation of periodic measurements, whereby, following a period of time, reference values for the average consumption are automatically accumulated and calculated for this period. With a device for metering and displaying energy consumption according to the invention, the user thus does not need have any knowledge of any data of the consumption history or presumed average and unit prices in order to be able to use the device. Furthermore, it is not necessary to update data when prices are changed. This means that such a xe2x80x9cconsumption meterxe2x80x9d according to the invention can be used also be users without technical skills, as it is easy to read and easy to interpret visually. Thus, with a consumption meter according to the invention, the user will be inspired to cut down on the energy consumption concerned, without possessing previous technical knowledge with respect to the various metering units for the various types of energy consumption.
Since exclusively a percentage scale is used for the display, the consumption meter according to the invention requires no knowledge of which metering units are used, and no knowledge about how absolute values are to be interpreted. This interpretation is performed by the calculations and display of the device. According to the invention, the relationship between the accumulated consumption and an average consumption e.g. for 24 hours is shown. As the consumption increases, the accumulated consumption approaches the average consumption and perhaps exceeds it in percentage. It has thus been realized by the invention that the absolute values of the given energy consumption, such as e.g. the electricity consumption, are not needed at all in order to have a reliable indication of the topical energy consumption in relation to what it usually is.
In the preferred embodiment of the invention, the display moreover has a second display unit capable of displaying the immediate power consumption relative to a selected reference consumption, preferably on a percentage power scale from 0-100%, the selected reference consumption, which corresponds to the maximally recorded power, corresponding to 80% on the power scale. It is hereby ensured with a consumption meter according to the invention that the user will more easily be motivated to cut down on the energy, as he will immediately get a rapid visual indication in his energy consumption because of e.g. an energy saving measure, such as the use of low-energy bulbs in one or more lamps or the like.
In the preferred embodiment of the consumption meter, the accumulated energy consumption is displayed on the first display unit on an energy scale preferably from 0-200%, where 100% corresponds to the calculated average consumption. This means that the user can easily and visually quickly read the display and see how the accumulated energy consumption is relative to the average.
A particularly simple visual representation of the recorded and calculated values may be that the display units are constructed as column displays, each of which is formed by a plurality of linearly arranged light-emitting diodes (LED). This may additionally be made visually readily understandable if the energy scale exhibits LEDs which give out light in a first colour e.g. green, on the lower half of the scale, and the LEDs above 100% on the scale give out light in another colour, e.g. red.
With the consumption meter according to the invention, the period of time for the calculation of the average consumption and the interval of time for the accumulated display may be 24 hours, one week or one month. In the preferred embodiment, the device may be arranged to display the ratio of accumulated energy consumption over 24 hours in one display unit by default, but, by activation of another display function, may instead display history over one week or one month. This may be the immediately preceding month or week or a specific earlier week/month. If it is the latter, another display unit will indicate how many weeks/months the displayed energy consumption dates back.
According to a preferred embodiment of the recording unit, it records the immediate energy consumption using a pulse generator which initiates a measurement preferably every second. Frequent measurements are obtained hereby, and as a result of this the consumption meter according to the invention visualizes even small changes in the energy consumption. This gives the reader a quick and good indication of where energy is used in the household, and the amount contributed by the individual units of consumption, such as refrigerators, ceiling lamps or the like, to the overall consumption.
The consumption meter may moreover be provided with an interface for connection to a computer for exchange of data between the device and the computer. The consumption meter according to the invention may hereby be provided with reference values, if it is not desired to use the self-calibrating function. The interface may moreover be used for the transfer of data from the consumption meter to a PC, if it is desired to perform statistical calculations or the like on the basis of the recorded figures of consumption.
It is realized in connection with the invention that the consumption meter may be used in connection with the display of electricity, water or heating consumption, together with visualization of e.g. gas or oil consumption, just as electricity production from solar cell systems or wind mills may be visualized proportionally relative to e.g. immediate energy consumption, average electricity production or the like.
In the preferred embodiment, the device is provided with an operating panel for the selection of various display functions. In this embodiment, the operating panel comprises two keys which are preferably formed as oppositely directed arrows, by means of which the desired display function may be selected from the sequentially arranged display functions. This ensures simple and easy operation of the consumption meter according to the invention.
The invention also comprises a method of metering and displaying immediate and/or accumulated energy consumption at a place of consumption, such as electricity, water or heating consumption in a household, which is characterized in that an immediate energy consumption is recorded on the basis of regular measurements, and that this measurement is stored and an average consumption is calculated for a given period of time, that an accumulated energy consumption is calculated and displayed on a display which displays, on at least one percentage scale, the relationship between an accumulated energy consumption and the calculated average consumption for a given period of time.
The invention additionally comprises a method of calibrating a device as stated in the foregoing, said method being characterized in that, after the installation of the device, calibration is automatically performed through accumulation of periodic measurements.